Compounds containing boron and aluminium

ABSTRACT

The present invention relates to a chemical compound of the formula A                    
     The compound can be employed as a catalyst component for the polymerization of olefins.

The present invention relates to a chemical compound which, incombination with a metallocene, can form a catalyst system which canadvantageously be employed for the polymerization of olefins. The use ofan aluminoxane, such as methylaluminoxane (MAO), as cocatalyst isunnecessary in this polymerization, and yet high catalyst activity isstill achieved.

The role of cationic complexes in Ziegler-Natta polymerization usingmetallocenes is generally recognized (H. H. Brintzinger, D. Fischer, R.Mülhaupt, R. Rieger, R. Waymouth, Angew. Chem. 1995, 107, 1255-1283). Asthe most effective cocatalyst hitherto, MAO has the disadvantage ofbeing employed in a large excess, which results in a high aluminumcontent in the polymer. The preparation of cationic alkyl complexesgives access to MAO-free catalysts of comparable activity, where thecocatalyst can be employed in a virtually stoichiometric amount.

The synthesis of “cation-similar” metallocene polymerization catalystsis described in J. Am. Chem. Soc. 1991, 113, 3623. This synthesisinvolves alkyl abstraction from an alkyl metallocene compound by meansof trispentafluorophenylborane. EP 427 697 claims this syntheticprinciple and a corresponding catalyst system consisting of a neutralmetallocene species (for example CP₂ZrMe₂), a Lewis acid (for exampleB(C₆F₅)₃) and alkylaluminum compounds. A process for the preparation ofsalts of the general form LMX⁺XA⁻ by the above-described principle isclaimed in EP 520 732.

Disadvantages of known alternative cocatalyst systems are their highsensitivity to catalyst poisons and the problem of leaching onsupporting of the catalyst systems.

The object of the present invention was to provide a chemical compoundwhich avoids the disadvantages of the prior art and neverthelessfacilitates high polymerization activities.

The present invention thus relates to a novel chemical compound and to aprocess for the preparation of this chemical compound. It furthermorerelates to a catalyst system comprising at least one metallocene and atleast one chemical compound according to the invention as cocatalyst.The catalyst system may additionally comprise further organometalliccomponents and be immobilized on a support material. Furthermore, aprocess for the preparation of polyolefins is described.

The object is achieved by a chemical compound of the formula A

in which R¹ are identical or different and are a hydrogen atom, ahalogen atom, a boron-free C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R¹ can be an OSiR³ ₃ group,in which R³ are identical or different and are a hydrogen atom, ahalogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R¹ can be a CH(SiR⁴ ₃)₂group in which R⁴ may be identical or different and are a hydrogen atom,a halogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-halo-alkylaryl,

X is identical or different and is an element from group VIa of thePeriodic Table of the Elements or is an NR group, where R is hydrogen ora C₁-C₂₀-hydrocarbon radical, such as C₁-C₂₀-alkyl or C₁-C₂₀-aryl,

R^(a) and R^(b) may be identical or different and are a hydrogen atom, ahalogen atom, a boron-free C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R¹ can be an OSiR³ ₃ group,in which R³ are identical or different and are a hydrogen atom, ahalogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl,

In addition, R^(a) and R^(b) can be a boron-containing group, such as,for example, —X—BR¹ ₂, in which X is an element from group VIa of thePeriodic Table of the Elements or an NR group, where R is hydrogen or aC₁-C₂₀-hydrocarbon radical, such as C₁-C₂₀-alkyl or C₁-C₂₀-aryl, and R¹are identical or different and are a hydrogen atom, a halogen atom, aboron-free C₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, or R¹ can be an OSiR³ ₃ group, in which R³ areidentical or different and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, or R¹ can be a CH(SiR⁴ ₃)₂ group, in which R⁴are identical or different and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, and k is an integer from 1 to 100.

The compound of the formula A according to the invention can formdimers, trimers or higher oligomers through acid-base interactions,where k can be a natural number from 1 to 100.

Preferred chemical compounds of the formula A conform to the generalformulae I, II and III:

in which R¹ are identical or different and are a hydrogen atom, ahalogen atom, a boron-free C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R¹ can be an OSiR³ ₃ group,in which R³ are identical or different and are a hydrogen atom, ahalogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R¹ can be a CH(SiR⁴ ₃)₂group in which R⁴ may be identical or different and are a hydrogen atom,a halogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-halo-lkylaryl,

R² may be identical or different and are a hydrogen atom, a halogenatom, a boron-free C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl, or R² can be an OSiR³ ₃ group,in which R³ are identical or different and are a hydrogen atom, ahalogen atom, a C₁-C₄₀-hydrocarbon-containing group, such asC₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-aryl-alkyl,C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl.

X is identical or different and is an element from group VIa of thePeriodic Table of the Elements or is an NR group, where R is hydrogen ora C₁-C₂₀-hydrocarbon radical, such as C₁-C₂₀-alkyl or C₁-C₂₀-aryl.

The compounds of the formulae I-III according to the invention can formdimers, trimers and higher oligomers with one another through acid-baseinteractions, where k can be an integer from 1 to 100.

Particular preference is given to compounds of the formulae I-III inwhich X is an oxygen atom or a NH group.

R¹ is preferably a boron-free C₁-C₄₀-hydrocarbon radical, which may behalogenated, preferably perhalogenated, by halogen, such as fluorine,chlorine, bromine or iodine, in particular a halogenated, preferablyperhalogenated, C₁-C₃₀-alkyl group, such as trifluoromethyl,pentachloroethyl, heptafluoroisopropyl or monofluoroisobutyl, or ahalogenated, preferably perhalogenated, C₆-C₃₀-aryl group, such aspentafluorophenyl, heptachloronaphthyl, heptafluoronaphthyl,heptafluorotolyl, 3,5-bis(trifluoromethyl)phenyl,2,4,6-tris(trifluoromethyl)phenyl or 4-(trifluoromethyl)phenyl. R¹ canlikewise preferably be radicals such as phenyl, methyl, ethyl,isopropyl, butyl, tolyl or 2,3-dimethylphenyl. Particular preference isgiven to the radicals pentafluorophenyl, phenyl,3,5-bis(trifluoromethyl)phenyl and 4-methylphenyl.

R² is preferably a hydrogen atom or a boron-free C₁-C₄₀-hydrocarbonradical, which may be halogenated, preferably perhalogenated, byhalogen, such as fluorine, chlorine, bromine or iodine, in particular ahalogenated, preferably perhalogenated, C₁-C₃₀-alkyl group, such astrifluoromethyl, pentachloroethyl, heptafluoroisopropyl ormonofluoroisobutyl, or a halogenated, preferably perhalogenated,C₆-C₃₀-aryl group, such as pentafluorophenyl, heptachloronaphthyl,heptafluoronaphthyl, heptafluorotolyl, 3,5-bis(trifluoromethyl)phenyl,2,4,6-tris(trifluoromethyl)phenyl or 4-(trifluoromethyl)phenyl. R² canlikewise preferably be radicals such as phenyl, methyl, ethyl,isopropyl, butyl, tolyl, -4-methyl phenyl or 2,3-dimethylphenyl.Particular preference is given to the radicals pentafluorophenyl,phenyl, 3,5-bis(trifluoromethyl)phenyl, 4-methylphenyl, methyl, ethyl,isopropyl, butyl and propyl. k is preferably an integer from 1 to 10,particularly preferably 1, 2, 3 or 4.

Compounds of the formula A are obtainable by reactinghydroxyorganoborines of the formula IV or diorganoborinic anhydrides ofthe formula V with organoaluminum compounds of the formula VI

in which R⁶ is a hydrogen atom or a boron-freeC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl, C₆-C₂₀-aryl,C₇-C₄₀-arylalky or C₇-C₄₀-alkylaryl, and in which R¹ are identical ordifferent and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, or R¹ can be an OSiR³ ₃ group, in which R³ areidentical or different and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, or R¹ can be a CH(SiR⁴ ₃)₂ group in which R⁴may be identical or different and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-halo-alkylaryl.

R¹ are identical or different and are preferably a boron-freeC₁-C₄₀-hydrocarbon radical, which may be halogenated, preferablyperhalogenated, by halogen, such as fluorine, chlorine, bromine oriodine, in particular a halogenated, preferably perhalogenated,C₁-C₃₀-alkyl group, such as trifluoromethyl, pentachloroethyl,heptafluoroisopropyl or monofluoroisobutyl, or a halogenated, preferablyperhalogenated, C₆-C₃₀-aryl group, such as pentafluorophenyl,heptachloronaphthyl, heptafluoronaphthyl, heptafluorotolyl,3,5-bis(trifluoromethyl)phenyl, 2,4,6-tris(trifluoromethyl)phenyl or4-(trifluoromethyl)phenyl. R¹ can likewise preferably be radicals suchas phenyl, biphenyl, naphthyl, anisyl, methyl, ethyl, isopropyl, butyl,tolyl or 2,3-dimethylphenyl. R² may be identical or different and are ahydrogen atom, a halogen atom, a boron-freeC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylarylor C₇-C₄₀-haloalkylaryl, or R² can be an OSiR³ ₃ group, in which R³ areidentical or different and are a hydrogen atom, a halogen atom, aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-aryl-alkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl or C₇-C₄₀-haloalkylaryl.

R² is preferably a hydrogen atom, a halogen atom or a boron-freeC₁-C₄₀-hydrocarbon radical, which may be halogenated, preferablyperhalogenated, by halogen, such as fluorine, chlorine, bromine oriodine, in particular a halogenated, go preferably perhalogenated,C₁-C₃₀-alkyl group, such as trifluoromethyl, pentachloro-ethyl,heptafluoroisopropyl or monofluoroisobutyl, or a halogenated, preferablyperhalogenated, C₆-C₃₀-aryl group, such as pentafluorophenyl,heptachloronaphthyl, heptafluoronaphthyl, heptafluorotolyl,3,5-bis(trifluoromethyl)phenyl, 2,4,6-tris(trifluoromethyl)phenyl or4-(trifluoromethyl)phenyl. R² can likewise preferably be radicals suchas phenyl, methyl, ethyl, isopropyl, butyl, tolyl or 2,3-dimethylphenyl.X are identical or different and are an element from group VIa of thePeriodic Table of the Elements or an NR group, in which R is a hydrogenatom or a C₁-C₂₀-hydrocarbon radical, such as C₁-C₂₀-alkyl orC₁-C₂₀-aryl, and n is an integer from 1 to 10. n is preferably 1, 2, 3or 4. Preference is given to compounds in which X is an oxygen atom oran NH group.

Examples of compounds of the formulae IV and V are the following:

di(pentafluorophenyl)borinic acid

di(phenyl)borinic acid

di(o-tolyl)borinic acid

di(m-tolyl)borinic acid

di(p-tolyl)borinic acid

di(p-anisyl)borinic acid

di(p-biphenyl)borinic acid

di(p-chlorophenyl)borinic acid

di(α-naphthyl)borinic acid

di(ethyl)borinic acid

di(butyl)borinic acid

di(methyl)borinic acid

di(isopropyl)borinic acid

di(propyl)borinic acid

di(isobutyl)borinic acid

di(butyl)borinic acid

di(vinyl)borinic acid

dibis(trimethylsilyl)methylborinic acid

di(p-fluorophenyl)borinic acid

di(p-bromophenyl)borinic acid

di(mesityl)borinic acid

di(cyclohexyl)borinic acid

tert-butyl-phenylborinic acid

di(2-vinylphenyl)borinic acid

methylphenylborinic acid

ethyiphenylborinic acid

1-naphthylphenylborinic acid

di(cyclopentyl)borinic acid

di(ethyl)borinic anhydride

di(propyl)borinic anhydride

di(isopropyl)borinic anhydride

di(butyl)borinic anhydride

di(isobutyl)borinic anhydride

di(sec-butyl)borinic anhydride

di(allyl)borinic anhydride

di(methyl)borinic anhydride

di(phenyl)borinic anhydride

di(pentafluorophenyl)borinic anhydride

di(p-tolyl)borinic anhydride

di(1-naphthyl)borinic anhydride

di(mesityl)borinic anhydride

di(methylphenyl)borinic anhydride

di(3,5-bistrifluoromethylphenyl)borinic anhydride

diphenylboranylamine

dimethylboranylamine

dibutylboranylamine

diethylboranylamine

ethylmethylboranylamine

diisopropylboranylamine

diisopropylboranylamine

di-p-tolylboranylamine

dimesitylboranylamine

di-1-naphthylboranylamine

aminodibis(trimethylsilyl)methylborane

Examples of compounds of the formula VI are the following:

trimethylaluminum

triethylaluminum

triisopropylaluminum

trihexylaluminum

trioctylaluminum

tri-n-butylaluminum

tri-n-propylaluminum

triisoprenealuminum

dimethylaluminum monochloride

diethylaluminum monochloride

diisobutylaluminum monochloride

methylaluminum sesquichloride

ethylaluminum sesquichloride

dimethylaluminum hydride

diethylaluminum hydride

diisopropylaluminum hydride

dimethylaluminum trimethylsiloxide

dimethylaluminum triethylsiloxide

phenylalane

pentafluorophenylalane

o-tolylalane

For the preparation of the cocatalytic organoboron-aluminum compound ofthe formula A, one or more compounds of the formulae IV and V can bereacted with one or more compounds of the formula VI in any desiredstoichiometric ratio, preferably in an amount of from 2 to 6 equivalentsof a compound of the formula IV or V with one equivalent of the formulaVI, particularly preferably in an amount of from 2 to 2.5 equivalents ofa compound of the formula IV or V with one equivalent of the formula VI.

The reaction is carried out in an aliphatic or aromatic solvent, such astoluene, heptane, tetrahydrofuran or diethyl ether. It is also possibleto use solvent mixtures. The cocatalytic organoboron-aluminum compoundsof the formula A can be isolated or reacted further in solution withoutisolation. The term solution or solvent is also taken to mean asuspension or suspending medium, i.e. the starting materials employed inthe process according to the invention and the products obtained can bepartially or fully dissolved or partially or fully suspended.

Illustrative examples of the chemical compound of the formula Aaccording to the invention are the following:

The chemical compound of the formula A according to the invention can beused together with a transition-metal compound as catalyst system, forexample for the polymerization of olefins. The transition-metal compoundemployed is a metallocene compound. This can be, for example, a bridgedor unbridged biscyclopentadienyl complex, as described, for example, inEP 129 368, EP 561 479, EP 545 304 and EP 576 970, monocyclopentadienylcomplexes, such as bridged amidocyclopentadienyl complexes, which aredescribed, for example, in EP 416 815, polycyclic pentadienyl complexes,as described in EP 632 063, tetrahydropentalenes substituted byπ-ligands, as described in EP 659 758, or tetrahydroindenes substitutedby π-ligands, as described in EP 661 300.

Preferred metallocene compounds are unbridged or bridged compounds ofthe formula VII

in which

M¹ is a metal from sub-group III, IV, V or VI of the Periodic Table ofthe Elements, in particular Ti, Zr or Hf,

R′ are identical or different and are a hydrogen atom or SiR^(3′) ₃, inwhich R^(3′) are identical or different and are a hydrogen atom or aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₁₀-fluoroalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₁₀-fluoroaryl,C₆-C₁₀-aryloxy, C₂-C₁₀-alkenyl, C₇-C₄₀-arylalkyl, C₇-C₄₀-alkylaryl orC₈-C₄₀-arylalkenyl, or R′ are a C₁-C₃₀-hydrocarbon-containing group,such as C₁-C₂₅-alkyl, for example methyl, ethyl, tert-butyl, cyclohexylor octyl, C₂-C₂₅-alkenyl, C₃-C₁₅-alkylalkenyl, C₆-C₂₄-aryl,C₅-C₂₄-heteroaryl, such as pyridyl, furyl or quinolyl, C₇-C₃₀-arylalkyl,C₇-C₃₀-alkylaryl, fluorine-containing C₁-C₂₅-alkyl, fluorine-containingC₆-C₂₄-aryl, fluorine-containing C₇-C₃₀-arylalkyl, fluorine-containingC₇-C₃₀-alkylaryl or C₁-C₁₂-alkoxy, or two or more radicals R′ may beconnected to one another in such a way that the radicals R′ and thecyclopentadienyl ring atoms connecting them form a C₄-C₂₄-ring system,which may itself be substituted,

R″ are identical or different and are a hydrogen atom or SiR^(3′) ₃, inwhich R^(3′) are identical or different and are a hydrogen atom or aC₁-C₄₀-hydrocarbon-containing group, such as C₁-C₂₀-alkyl,C₁-C₁₀-fluoroalkyl, C₁-C₁₀-alkoxy, C₆-C₁₄-aryl, C₆-C₁₀-fluoroaryl,C₆-C₁₀-aryloxy, C₂-C₁₀-alkenyl, C₇-C₄₀-arylalkyl, C₇-C₄₀-alkylaryl orC₈-C₄₀-arylalkenyl, or R″ are a C₁-C₃₀-hydrocarbon-containing group,such as C₁-C₂₅-alkyl, for example methyl, ethyl, tert-butyl, cyclohexylor octyl, C₂-C₂₅-alkenyl, C₃-C₁₅-alkylalkenyl, C₆-C₂₄-aryl,C₅-C₂₄-heteroaryl, such as pyridyl, furyl or quinolyl, C₇-C₃₀-arylalkyl,C₇-C₃₀-alkylaryl, fluorine-containing C₁-C₂₅-alkyl, fluorine-containingC₆-C₂₄-aryl, fluorine-containing C₇-C₃₀-arylalkyl, fluorine-containingC₇-C₃₀-alkylaryl or C₁-C₁₂-alkoxy, or two or more radicals R″ may beconnected to one another in such a way that the radicals R″ and thecyclopentadienyl ring atoms connecting them form a C₄-C₂₄-ring system,which may itself be substituted,

l is 5 when v=0, and l is 4 when v=1,

m is 5 when v=0, and m is 4 when v=1,

L¹ may be identical or different and are a hydrogen atom, a halogen atomor a C₁-C₁₀-alkyl group, a C₇-C₄₀-arylalkyl group, a C₆-C₄₀-aryl group,or OR^(6′), SR^(6′), OSiR^(6′) ₃, SiR^(6′) ₃, PR^(6′) ₂ or NR^(6′) ₂, inwhich R^(6′) is a halogen atom, a C₁-C₁₀-alkyl group, a halogenatedC₁-C₁₀-alkyl group, a C₆-C₂₀-aryl group or a halogenated C₆-C₂₀-arylgroup, or L¹ are a toluenesulfonyl, trifluoroacetyl, trifluoroacetoxyl,trifluoromethanesulfonyl, nonafluorobutanesulfonyl or2,2,2-trifluoroethanesulfonyl group,

o is an integer from 1 to 4, preferably 2,

Z is a bridging structural unit between the two cyclopentadienyl rings,and

v is 0 or 1.

Examples of Z are M²R^(5′)R⁵ groups, in which M² is carbon, silicon,germanium or tin, and R^(5′) and R⁵ are identical or different and are aC₁-C₂₀-hydrohydrocarbon-containing group, such as C₁-C₁₀-alkyl,C₆-C₁₄-aryl or trimethylsilyl. Z is preferably CH₂, CH₂CH₂, CH(CH₃)CH₂,CH(C₄H₉)C(CH₃)₂, C(CH₃)₂, (CH₃)₂Si, (CH₃)₂Ge, (CH₃)₂Sn, (C₆H₅)₂Si,(C₆H₅)(CH₃)Si, (C₆H₅)₂Ge, (C₆H₅)₂Sn, (CH₂)₄Si, CH₂Si(CH₃)_(2, o-C) ₆H₄or 2,2′-(C₆H₄)₂. Z can also form a monocyclic or polycyclic ring systemtogether with one or more radicals R′ and/or R″.

Preference is given to chiral, bridged metallocene compounds of theformula VII, in particular those in which v is 1 and one or twocyclopentadienyl rings are substituted in such a way that they form anindenyl ring. The indenyl ring is preferably substituted, in particularin the 2-, 4-, 2,4,5-, 2,4,6-, 2,4,7- or 2,4,5,6-position, byC₁-C₂₀-hydrocarbon-containing groups, such as C₁-C₁₀-alkyl orC₆-C₂₀-aryl, it also being possible for two or more substituents on theindenyl ring together to form a ring system.

Chiral, bridged metallocene compounds of the formula (VII) can beemployed as pure racemic or pure meso compounds. However, it is alsopossible to use mixtures of a racemic compound and a meso compound.

Examples of metallocene compounds are the following:

dimethylsilanediylbis(indenyl)zirconium dichloride

dimethylsilanediylbis(4-naphthylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methylbenzoindenyl)zirconium dichloride

dimethylsilanediylbis(2-methylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-t-butylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4-ethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-acenaphthindenyl)zirconium dichloride

dimethylsilanediylbis(2,4-dimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-ethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4,5-diisopropylindenyl)zirconiumdichloride

dimethylsilanediylbis(2,4,6-trimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2,5,6-trimethylindenyl) zirconium dichloride

dimethylsilanediylbis(2,4,7-trimethylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-5-isobutylindenyl)zirconium dichloride

dimethylsilanediylbis(2-methyl-5-t-butylindenyl)zirconium dichloride

methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-5isobutylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-(methylindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)indenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methyl-4-acenaphthindenyl)zirconiumdichloride

methyl(phenyl)silanediylbis(2-methylindenyl)zirconium dichloride

methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)zirconiumdichloride

1,2-ethanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride

1,2-ethanediylbis(2-methyl-4,6 diisopropylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride

1,4-butanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride

1,2-ethanediylbis(2,4,7-trimethylindenyl)zirconium dichloride

1,2-ethanediylbis(2-methylindenyl)zirconium dichloride

1,4-butanediylbis(2-methylindenyl)zirconium dichloride

[4-(η⁵-cyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]-dichlorozirconium

[4-(η⁵-3′-trimethylsilylcyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]dichlorozirconium

[4-(η⁵-3′-isopropyl-cyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]dichlorozirconium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dichlorotitanium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dichlorozirconium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dichlorohafnium

[4-(η⁵-3′-tert-butylcyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dichlorotitanium

4-(η⁵-3′-isopropylcyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dichlorotitanium

4-(η⁵-3′-methylcyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dichlorotitanium

4-(η⁵-3′-trimethylsilylcyclopentadienyl)-2-trimethylsilyl-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dichlorotitanium

4-(η⁵-3′-tert-butylcyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dichlorozirconium

(tertbutylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilyldichlorotitanium

(tertbutylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyldichlorotitanium

(methylamido)(tetramethyl-η⁵-cyclopentadienyl)dimethylsilyldichlorotitanium

(methylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyldichlorotitanium

(tertbutylamido)(2,4-dimethyl-2,4-pentadien-1-yl)dimethylsilyldichlorotitanium

bis(cyclopentadienyl)zirconium dichloride

bis(n-butylcyclopentadienyl)zirconium dichloride

bis(1,3-dimethylcyclopentadienyl)zirconium dichloride

tetrachloro[1-[bis(η⁵-1H-inden-1-ylidene)methylsilyl]-3-η⁵-cyclopenta-2,4-dien-1-ylidene)-3-η⁵-9H-fluoren-9-ylidene)butane]dizirconium

tetrachloro[2-[bis(η⁵-2-methyl-1H-inden-1-ylidene)methoxysilyl]-5-(η⁵-2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)-5-(η⁵-9H-fluoren-9-ylidene)hexane]dizirconium

tetrachloro[1-[bis(η⁵-1H-inden-1-ylidene)methylsilyl]-6-(η⁵-cyclopenta-2,4-dien-1-ylidene)-6-(η⁵-9H-fluoren-9-ylidene)-3-oxaheptane]dizirconium

dimethylsilanediylbis(indenyl)zirconiumdimethyl

dimethylsilanediylbis(4-naphthylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methylbenzoindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-t-butylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-isopropylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-ethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4-acenaphthindenyl)zirconiumdimethyl

dimethylsilanediylbis(2,4-dimethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-ethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-ethyl-4-ethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4,6 diisopropylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-4,5 diisopropylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2,4,6-trimethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2,5,6-trimethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2,4,7-trimethylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-5-isobutylindenyl)zirconiumdimethyl

dimethylsilanediylbis(2-methyl-5-t-butylindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4,5-(methylbenzo)indenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)indenyl)-zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-4-acenaphthindenyl)zirconium-dimethyl

methyl(phenyl)silanediylbis(2-methylindenyl)zirconiumdimethyl

methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)zirconiumdimethyl

1,2-ethanediylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl

1,4-butanediylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl

1,2-ethanediylbis(2-methyl-4,6-diisopropylindenyl)zirconiumdimethyl

1,4-butanediylbis(2-methyl-4-isopropylindenyl)zirconiumdimethyl

1,4-butanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdimethyl

1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)zirconiumdimethyl

1,2-ethanediylbis(2,4,7-trimethylindenyl)zirconiumdimethyl

1,2-ethanediylbis(2-methylindenyl)zirconiumdimethyl

1,4-butanediylbis(2-methylindenyl)zirconiumdimethyl

[4-(η⁵-cyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]-dimethylzirconium

[4-(η⁵-3′-trimethylsilylcyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]dimethylzirconium

[4-(η⁵-3′-isopropylcyclopentadienyl)-4,6,6-trimethyl-(η⁵-4,5-tetrahydropentalene)]dimethylzirconium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dimethyltitanium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dimethylzirconium

[4-(η⁵-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]-dimethylhafnium

[4-(η⁵-3′-tert-butyl-cyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dimethyltitanium

4-(η⁵-3′-isopropylcyclopentadienyl)-4,7,7-trimethyl-(η⁵-4,5,6,7-tetrahydroindenyl)]dimethyltitanium

dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)hafnuimdichloride

dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)titaniumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-methylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-ethylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-n-propylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-isopropylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-n-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-hexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-sec-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-phenyl)indenyl)zirconium dichloride

dimethylsilanediylbis(2-ethyl-4-(4′-methylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-ethylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-n-propylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-isopropylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-n-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-hexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-pentylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-cyclohexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-sec-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-phenyl)indenyl)zirconium dichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-methylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-ethylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-n-propylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-isopropylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-n-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-hexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-cyclohexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-sec-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-propyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-phenyl)indenyl)zirconium dichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-methylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-ethylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-n-propylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-isopropylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-n-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-hexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-cyclohexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-sec-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-n-butyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-phenyl)indenyl)zirconium dichloride

dimethylsilanediylbis(2-hexyl-4-(4′-methylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-ethylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-n-propylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2hexyl-4(4′-isopropylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-n-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-hexylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-sec-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-hexyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumbis(dimethylamide)

dimethylsilanediylbis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdibenzyl

dimethylsilanediylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdimethyl

dimethylgermandiylbis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylgermandiylbis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)hafniumdichloride

dimethylgermandiylbis(2-propyl-4-(4′-tert-butylphenyl)indenyl)titaniumdichloride

dimethylgermandiylbis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

ethylidenebis(2-ethyl-4-phenyl)indenyl)zirconium dichloride

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

ethylidenebis(2-n-propyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

ethylidenebis(2-n-butyl-4-(4′-tert-butylphenyl)indenyl)titaniumdichloride

ethylidenebis(2-hexyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdibenzyl

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)hafniumdibenzyl

ethylidenebis(2-methyl-4-(4′-tert-butylphenyl)indenyl)titaniumdibenzyl

ethylidenebis(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)hafniumdimethyl

ethylidenebis(2-n-propyl-4-phenyl)indenyl)titaniumdimethyl

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumbis(dimethylamide)

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)hafniumbis(dimethylamide)

ethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)titaniumbis(dimethylamide)

methylethylidenebis(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

methylethylidenebis(2ethyl-4-(4′-tert-butylphenyl)indenyl)hafniumdichloride

phenylphosphanediyl(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

phenylphosphanediyl(2-methyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

phenylphosphanediyl(2-ethyl-4-(4′-tert-butylphenyl)indenyl)zirconiumdichloride

dimethylsilanediyl(indenyl)zirconium dichloride

dimethylsilanediyl(4-naphthylindenyl)zirconium dichloride

dimethylsilanediyl(2-methylbenzoindenyl)zirconium dichloride

dimethylsilanediyl(2-methylindenyl)zirconium dichloride

dimethylsilanediyl(2-methyl-4-phenylindenyl)zirconium dichloride

dimethylsilanediyl(2-methyl-4-(1-naphthyl)indenyl)zirconium dichloride

dimethylsilanediyl(2-methyl-4-(2-naphthyl)indenyl)zirconium dichloride

dimethylsilanediyl(2-methyl-4-isopropylindenyl)zirconium dichloride

dimethylsilanediyl(2-methyl-4-acenaphthylindenyl)zirconium dichloride

In order to prepare the catalyst system according to the invention, oneor more compounds of the formula A can be reacted with a metallocenecompound, for example of the formula VlI, in any desired stoichiometricratio. If desired, one or more compounds of the formula VI canadditionally be added in any desired stoichiometric ratio.

In the preparation of the catalyst system according to the invention,preference is given to an Al:M¹ molar ratio between the compounds of theformula A and of the formula VII of from 0.01 to 100,000, particularlypreferably from 0.1 to 1000, very particularly preferably from 1 to 100.To this end, a compound of the formula VI can additionally be added inan Al:M¹ molar ratio of from 0.01 to 10,000, preferably from 0.1 to1000, very particularly preferably from 1 to 100.

The compounds can be brought into contact with one another in anypossible sequence. A possible procedure is to dissolve or suspend anorganotransition-metal compound of the formula VII in an aliphatic oraromatic solvent. An organoboron-aluminum compound of the formula A isthen added either as such or in dissolved or suspended form. Thereaction time is between 1 minute and 24 hours, preferably between 5minutes and 120 minutes. The reaction temperature is between −10° C. and+200° C., preferably between 0° C. and 50° C. A compound of the formulaVI in dissolved or suspended form is then added. The reaction time isbetween 1 minute and 24 hours, preferably between 5 minutes and 120minutes. The reaction temperature is between −10° C. and +200° C.,preferably between 0° C. and 50° C. The individual components can alsobe introduced into the polymerization reactor successively, in anydesired sequence, or one or more compounds of the formulae IV and Vreact in a solvent with one or more compounds of the formula VI to giveone or more compounds of the formula A. These are introduced into thepolymerization reactor, and one or more compounds of the formula VI isthen metered in.

The catalyst systems according to the invention can be employed for thepolymerization in unsupported or supported form. The support preferablycomprises at least one inorganic oxide, such as silicon oxide, aluminumoxide, zeolites, MgO, ZrO₂, TiO₂, B₂O₃, CaO, ZnO, ThO₂, Na₂CO₃, K₂CO₃,CaCO₃, MgCO₃, Na₂SO₄, Al₂(SO₄)₃, BaSO₄, KNO₃, Mg(NO₃)₂, Al(NO₃)₃, Na₂O,K₂O, or Li₂O, in particular silicon oxide and/or aluminum oxide. Thesupport can also comprise at least one polymer, for example ahomopolymer or copolymer, a crosslinked polymer or a polymer blend.Examples of polymers are polyethylene, polypropylene, polybutene,polystyrene, polystyrene crosslinked with divinylbenzene, polyvinylchloride, acrylate-butadiene-styrene copolymer, polyamide,polymethacrylate, polycarbonate, polyester, polyacetal or polyvinylalcohol.

The support can have a specific surface area in the range from 10 to1000 m²/g, preferably from 150 to 500 m²/g. The mean particle size ofthe support can be from 1 to 500 μm, preferably from 5 to 350 μm,particularly preferably from 10 to 200 μm.

The support is preferably porous, with a pore volume of from 0.5 to 4.0ml/g, preferably from 1.0 to 3.5 ml/g. A porous support has a certainproportion of cavities (pore volume). The shape of the pores is usuallyirregular, frequently spherical. The pores can be interconnected viasmall pore openings. The pore diameter is preferably from about 2 to 50nm. The particle shape of the porous support can be irregular orspherical and can be modified by mechanical, chemical or thermalaftertreatment. The particle size of the support can be modified asdesired by, for as example, cryogenic grinding and/or screening.

The support material may in addition have been pretreated with acompound of the formula VI. The compound of the formula VI can be thesame as that used for the preparation of the catalyst system, but mayalso be different therefrom. In addition, the support material may havebeen pretreated with other chemical compounds, such as, for example,trimethylchlorosilane, tetrachlorosilane, amines, such asphenyldimethylamine, pyridine, mercaptans, such asmercaptopropylmethyldimethoxysilane, benzyl chloride, phenylmethylchloride or tosylates.

The catalyst system according to the invention can be brought intocontact with the support in any possible combination. One variant is toprepare the catalyst system in solution and then to react it with thesupport. To this end, an organometallic compound, for example of theformula VII, is initially introduced in an aliphatic or aromaticsolvent, such as toluene, heptane, tetrahydrofuran or diethyl ether. Oneor more compounds of the formula A are subsequently added, either assuch or in dissolved form. The reaction time is between 1 minute and 24hours, preferably between 5 minutes and 120 minutes. The reactiontemperature is between −10° C. and +200° C., preferably between 0° C.and 50° C. An organoaluminum compound of the formula VI, either as suchor in dissolved or suspended form, is then added to the support. Thereaction time is again between 1 minute and 24 hours, preferably between5 minutes and 120 minutes. The reaction temperature is between −10° C.and +200° C., preferably between 0° C. and 50° C. All starting materialscan be employed in any desired stoichiometric ratio. The Al:M¹ molarratio between the compounds of the formula A and of the formula VII ispreferably from 0.1 to 1000, very particularly from 1 to 100. To thisend, a compound of the formula VII is preferably employed in a molarratio of from 0.1 to 1000, very particularly preferably from 1 to 100.The supported catalyst system can be employed directly for thepolymerization. However, it can also be employed for the polymerizationin resuspended form after removal of the solvent.

In addition, a process for the preparation of an olefin polymer in thepresence of the catalyst system according to the invention is described.The polymerization can be a homopolymerization or a copolymerization.

Preference is given to the polymerization of olefins of the formulaR^(α)—CH═CH—R^(β), in which R^(α) and R^(β) are identical or differentand are a hydrogen atom, a halogen atom, an alkoxy, hydroxyl,alkylhydroxyl, aldehyde, carboxyl or carboxylate group or a saturated orunsaturated hydrocarbon radical having 1 to 20 carbon atoms, inparticular 1 to 10 carbon atoms, which may be substituted by an alkoxy,hydroxyl, alkylhydroxyl, aldehyde, carboxyl or carboxylate group, orR^(α) and R^(β), together with the atoms connecting them, form one ormore rings. Examples of such olefins are 1-olefins, such as ethylene,propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, styrene,cyclic olefins, such as norbornene, vinylnorbornene, tetracyclododecene,ethylidenenorbornene, dienes, such as 1,3-butadiene or 1,4-hexadiene,biscyclopentadiene or methyl methacrylate.

In particular, propylene or ethylene is homopolymerized, ethylene iscopolymerized with one or more C₃-C₂₀-1-olefins, in particularpropylene, and/or with one or more C₄-C₂₀-dienes, in particular1,3-butadiene, or norbornene and ethylene are copolymerized.

The polymerization is preferably carried out at a temperature of from−60 to 300° C., particularly preferably from 30 to 250° C. The pressureis from 0.5 to 2500 bar, preferably from 2 to 1500 bar. Thepolymerization can be carried out continuously or batchwise, in one ormore steps, in solution, in suspension, in the gas phase or in asupercritical medium.

The supported catalyst system can be resuspended as a powder or withadherent solvent and metered into the polymerization system as asuspension in an inert suspending medium.

The catalyst system according to the invention can be used to carry outa prepolymerization, preferably using the (or one of the) olefin(s)employed in the polymerization.

In order to prepare olefin polymers having a broad molecular weightdistribution, preference is given to catalyst systems which contain twoor more different transition-metal compounds, for example metallocenes.

In order to remove catalyst poisons present in the olefin, purificationusing an alkylaluminum compound, for example trimethylaluminum,triethylaluminum or triisobutylaluminum, is advantageous. Thispurification can be carried out either in the polymerization systemitself, or the olefin is brought into contact with the Al compoundbefore introduction into the polymerization system, and is thenseparated again.

As molecular weight regulator and/or in order to increase the activity,hydrogen is added if necessary. The overall pressure in thepolymerization system is from 0.5 to 2500 bar, preferably from 2 to 1500bar. The compound according to the invention is used here in aconcentration, based on the transition metal, of, preferably from 10⁻³to 10⁻⁸ mol, preferably from 10⁻⁴ to 10⁻⁷ mol, of transition metal perdm³ of solvent or per dm³ of reactor volume.

Suitable solvents for the preparation of both the supported chemicalcompound according to the invention and of the catalyst system accordingto the invention are aliphatic or aromatic solvents, such as, forexample, hexane or toluene, ethereal solvents, such as, for example,tetrahydrofuran or diethyl ether, or halogenated hydrocarbons, such as,for example, methylene chloride, or halogenated aromatic hydrocarbons,such as, for example, o-dichlorobenzene.

Before addition of the catalyst system comprising at least one supportedchemical compound according to the invention and at least onetransition-metal compound (such as a metallocene), another alkylaluminumcompound, such as, for example, trimethylaluminum, triethylaluminum,triisobutylaluminum, trioctylaluminum or isoprenylaluminum, canadditionally be introduced into the reactor in order to render thepolymerization system inert (for example to remove catalyst poisonspresent in the olefin). This additional compound is added to thepolymerization system in a concentration of from 100 to 0.01 mmol of Alper kg of reactor contents. Preference is given to triisobutylaluminumand triethylaluminum in a concentration of from 10 to 0.1 mmol of Al perkg of reactor contents; this allows the molar Al:M ratio to be kept lowin the synthesis of a supported catalyst system.

The examples below serve to illustrate the invention in greater detail.

General information: the compounds were prepared and handled in theabsence of air and moisture under an argon blanket (Schlenk technique).All solvents required were rendered absolute before use by boiling for anumber of hours over suitable desiccants followed by distillation underargon.

Bis(pentafluorophenyl)borinic acid (R. D. Chambers et al., J. Chem.Soc., 1965, 3933) and bis(phenyl)borinic acid (G. E. Coates, J G.Livingstone, J. Chem. Soc. 1961, 4909) were prepared as described in theliterature.

1ST EXAMPLE Synthesis of di[bis(pentafluorophenylboroxy)]methylalane

5 ml of trimethylaluminum (2 M in toluene, 10 mmol) are introduced in 45ml of toluene. 6.92 g (20 mmol) of bis(pentafluorophenyl)borinic acid in50 ml of toluene are added dropwise to this solution over the course of15 minutes at −40° C. The mixture is stirred at −40° C. for 1 hour andthen at room temperature for a further hour. The slightly cloudy, paleyellow solution is filtered through a G4 frit, giving a clear, paleyellow solution (0.1 M, based on Al) ofbis(pentafluorophenylboroxy)methylalane in toluene.

2nd EXAMPLE Synthesis of di[bis(pentafluorophenylboroxy)]-methylalane

5 ml of trimethylaluminum (2 M in toluene, 10 mmol) are introduced in 45ml of toluene. 3.32 g (20 mmol) of bis(phenyl)borinic acid in 50 ml oftoluene are added dropwise to this solution over the course of 15minutes at −40° C. The mixture is stirred at −40° C. for 1 hour and thenat room temperature for a further hour. The slightly cloudy, pale yellowsolution is filtered through a G4 frit, giving a clear, pale yellowsolution (0.1 M, based on Al) of bis(phenylboroxy)methylalane intoluene.

3rd EXAMPLE Synthesis of di[bis(pentafluorophenylboroxy)]isopropylalane

10 ml of triisopropylaluminum (1 M in toluene, 10 mmol) are introducedin 50 ml of toluene. 6.92 g (20 mmol) of bis(pentafluorophenyl)borinicacid in 50 ml of toluene are added dropwise to this solution over thecourse of 15 minutes at −40° C. The mixture is stirred at −40° C. for 1hour and then at room temperature for a further hour. The clear solution(0.1 M, based on Al) of bis(pentafluorophenylboroxy)triisopropylalanecan be employed directly for the polymerization.

4th EXAMPLE Synthesis of di[bis(pentafluorophenylboroxy)]-isopropylalane

10 ml of triisopropylaluminum (1 M in toluene, 10 mmol) are introducedin 50 ml of toluene. 3.32 g (20 mmol) of bis(phenyl)borinic acid in 50ml of toluene are added dropwise to this solution over the course of 15minutes at −40° C. The mixture is stirred at −40° C. for 1 hour and thenat room temperature for a further hour. The clear solution (0.1 M, basedon Al) of bis(phenylboroxy)triisopropylalane can be employed directlyfor the polymerization.

5th EXAMPLE Preparation of the Catalyst System

9 ml of the cocatalyst stock solution prepared in Example 1 are added toa solution of 53 mg (90 μmol) ofdimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconiumdimethyl in10.75 ml of toluene. 0.25 ml of trimethylaluminum (2 M in toluene) arethen injected, and the mixture is stirred at room temperature for afurther hour. 0.5 ml of the stock solution prepared are employed forintroduction into the polymerization system.

6th EXAMPLE Polymerization

A 300 ml polymerization autoclave (Parr 4560) is charged with 150 ml ofheptane under an argon atmosphere. 1.1 ml of TIBA (20%) are then meteredin, and the mixture is stirred at 20° C. for 20 minutes. The reactor isthen heated to 50° C., and 0.5 ml of the catalyst solution preparedunder Example 5 are injected. Ethylene is then introduced to a pressureof 10 bar, and the polymerization is carried out for one hour atconstant ethylene pressure, giving 10.6 g of polyethylene powder. Thecatalyst activity is 8.08 kg of PE/g of metallocene×h.

7th EXAMPLE Preparation of the Catalyst System

10 g of SiO₂ (MS 3030, PQ company, dried at 600° C. in a stream ofargon) are added in portions to a solution of 100 mg (0.229 mmol) ofdimethylsilanediylbis(2-methylindenyl)zirconiumdimethyl in 25 ml oftoluene and 22.9 ml of the cocatalyst stock solution prepared inExample 1. The mixture is stirred at room temperature for one hour, andthe solvent is then removed to constant weight in an oil-pump vacuum. 1g of the supported catalyst are resuspended in 30 ml of Exxol forintroduction into the polymerization system.

8th EXAMPLE Polymerization

In parallel, a dry 16 dm³ reactor is flushed firstly with nitrogen andthen with propylene and charged with 10 dm³ of liquid propylene. 0.5 cm³of a 20% triisobutylaluminum solution in Varsol diluted with 30 cm³ ofExxol is then introduced into the reactor, and the batch is stirred at30° C. for 15 minutes. The catalyst suspension is then introduced intothe reactor. The reaction mixture is heated to the polymerizationtemperature of 60° C. (4° C./min), and the polymerization system is heldat 60° C. for 1 hour by cooling. The polymerization is terminated byventing the remaining propylene. The polymer is dried in a vacuum dryingcabinet, giving 1.7 kg of polypropylene powder. The reactor has nodeposits on the inside wall or stirrer. The catalyst activity is 174 kgof PP/g of metallocene×h.

What is claimed is:
 1. A compound of formula A

wherein R¹ represents identical or different radicals selected from thegroup consisting of hydrogen, C₁-C₂₀-haloalkyl, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl, C₇-C₄₀-haloalkylaryl, OSiR³ ₃ and CH(SiR⁴ ₃)₂; Xrepresents identical or different moieties selected from the groupconsisting of NR moieties and elements of group VIa of the PeriodicTable of the Elements; R^(a) and R^(b) represent identical or differentradicals selected from the group consisting of hydrogen, halogen,C₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl,C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl, C₇-C₄₀-haloalkylaryl, OSiR³ ₃ and X-BR¹ ₂; k is aninteger from 1 to 100; R³ represents identical or different radicalsselected from the group consisting of hydrogen, halogen, C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylaryland C₇-C₄₀-haloalkylaryl; R⁴ represents identical or different radicalsselected from the group consisting of hydrogen, halogen, C₁-C₂₀-alkyl,C₁-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylaryland C₇-C₄₀-haloalkylaryl; and R is hydrogen, C₁-C₂₀-alkyl orC₆-C₂₀-aryl.
 2. The compound of formula A defined in claim 1, which isobtained by reacting at least one compound of formula IV R¹ ₂B—XR⁶  (IV)wherein X is oxygen and R⁶ is hydrogen, with a compound of formula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 3. The compound of formula A defined in claim 1,which is obtained by reacting bis(pentafluorophenyl)borinic acid or itsanhydride with trimethylaluminum, triethylaluminum or withtriisopropylaluminum.
 4. A process for preparing the compound of formulaA defined in claim 1, which comprises reacting at least one compound offormula IV or V R¹ ₂B—XR⁶  (IV) R¹ ₂B—X—BR¹ ₂  (V) wherein R⁶ ishydrogen, C₁-C₂₀-alkyl, C₆-C₂₀-aryl, C₇-C₄₀-arylalkyl orC₇-C₄₀-alkylaryl, with a compound of formula VI

wherein R² represents identical or different radicals selected from thegroup consisting of hydrogen, halogen, C₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl,C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy,C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylaryl,C₇-C₄₀-haloalkylaryl and OSiR³ ₃; and n is an integer from 1 to
 10. 5.The process of claim 4, wherein at least one compound of formula IV R¹₂B—XR⁶  (IV) wherein X is oxygen and R⁶ is hydrogen, is reacted with acompound of formula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 6. The process of claim 4, whereinbis(pentafluorophenyl)-borinic acid is reacted with trimethylaluminum orwith triisopropylaluminum.
 7. A catalyst system comprising a) at leastone compound of formula A defined in claim 1, and b) at least onemetallocene compound, and optionally a support.
 8. The catalyst systemdefined in claim 7, comprising at least one compound of formula A whichis obtained by reacting at least one compound of formula IV R¹₂B—XR⁶  (IV) wherein X is oxygen and R⁶ is hydrogen, with a compound offormula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 9. The catalyst system defined in claim 7, comprisingat least one compound of formula A which is obtained by reactingbis(pentafluorophenyl)borinic acid or its anhydride withtrimethylaluminum, triethylaluminum or with triisopropylaluminum. 10.The catalyst system defined in claim 7, which is obtained by bringing atleast one compound of formula A into contact with at least onemetallocene compound and optionally a support.
 11. The catalyst systemdefined in claim 10, wherein at least one compound of formula A isobtained by reacting at least one compound of formula IV R¹ ₂B—XR⁶  (IV)wherein X is oxygen and R⁶ is hydrogen, with a compound of formula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 12. The catalyst system defined in claim 10, whereinat least one compound of formula A is obtained by reactingbis(pentafluorophenyl)borinic acid or its anhydride withtrimethylaluminum, triethylaluminum or with triisopropylaluminum. 13.The catalyst system defined in claim 10, which is obtained by i)reacting at least one compound of formula IV or V R¹ ₂B—XR⁶  (IV) R¹₂B—X—BR¹ ₂  (V)  wherein R⁶ is hydrogen, C₁-C₂₀-alkyl, C₆-C₂₀-aryl,C₇-C₄₀-arylalkyl or C₇-C₄₀-alkylaryl, with a compound of formula VI

 wherein R² represents identical or different radicals selected from thegroup consisting of hydrogen, halogen, C₁-C₂₀-alkyl,C_(l)-C₂₀-haloalkyl, C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl,C₆-C₂₀-aryloxy, C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl,C₇-C₄₀-alkylaryl, C₇-C₄₀-haloalkylaryl and OSiR³ ₃; and n is an integerfrom 1 to 10, to obtain a reaction mixture comprising at least onecompound of formula A, and ii) bringing the reaction mixture intocontact with at least one metallocene compound and optionally a support.14. The catalyst system defined in claim 13, wherein the reactionmixture is obtained by reacting at least one compound of formula IV R¹₂B—XR⁶  (IV) wherein X is oxygen and R⁶ is hydrogen, with a compound offormula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 15. The catalyst system defined in claim 13, whereinthe reaction mixture is obtained by reactingbis(pentafluorophenyl)borinic acid or its anhydride withtrimethylaluminum, triethylaluminum or with triisopropylaluminum.
 16. Aprocess for the manufacture of olefin homo- or copolymers, whichcomprises polymerizing identical or different olefins in the presence ofa catalyst system comprising a) at least one compound of formula A asdefined in claim 1, and b) at least one metallocene compound, andoptionally a support.
 17. The process of claim 16, wherein the catalystsystem comprises at least one compound of formula A which is obtained byreacting at least one compound of formula IV R¹ ₂B—XR⁶  (IV) wherein Xis oxygen and R⁶ is hydrogen, with a compound of formula VI

wherein R² represents identical or different C₁-C₂₀-alkyl radicals, andn is 1, 2, 3 or
 4. 18. The process of claim 16, wherein the catalystsystem comprises at least one compound of formula A which is obtained byreacting bis(pentafluorophenyl)borinic acid or its anhydride withtrimethylaluminum, triethylaluminum or with triisopropylaluminum. 19.The process of claim 16, wherein the catalyst system is obtained bybringing at least one compound of formula A into contact with at leastone metallocene compound and optionally a support.
 20. The process ofclaim 16, wherein the catalyst system is obtained by i) reacting atleast one compound of formula IV or V R¹ ₂B—XR⁶  (IV) R¹ ₂B—X—BR¹ ₂  (V) wherein R⁶ is hydrogen, C₁-C₂₀-alkyl, C₆-C₂₀-aryl, C₇-C₄₀-arylalkyl orC₇-C₄₀-alkylaryl, with a compound of formula VI

 wherein R² represents identical or different radicals selected from thegroup consisting of hydrogen, halogen, C₁-C₂₀-alkyl, C₁-C₂₀-haloalkyl,C₁-C₁₀-alkoxy, C₆-C₂₀-aryl, C₆-C₂₀-haloaryl, C₆-C₂₀-aryloxy,C₇-C₄₀-arylalkyl, C₇-C₄₀-haloarylalkyl, C₇-C₄₀-alkylaryl,C₇-C₄₀-haloalkylaryl and OSiR³ ₃; and n is an integer from 1 to 10, toobtain a reaction mixture comprising at least one compound of formula A,and ii) bringing the reaction mixture into contact with at least onemetallocene compound and optionally a support.